Experimental Investigation of Concrete Confinement using Custom Made CFRP Grid
Corrosion of steel reinforcement in coastal structures is a significant problem that greatly reduces the service life of these structures. The use of FRP reinforcement can provide a solution to this problem. However, the lack of ductility from the FRP reinforcement requires a different approach in the design for such structures. Failure is initiated in concrete and ductility is derived from concrete through confinement. This paper deals with the confinement provided by custom made embedded CFRP grid, manufactured into a circular shape and cast into the concrete in a similar configuration to spiral ties. In most cases confinement of concrete is achieved by wrapping concrete externally with FRP wraps. In this case the custom made CFRP grid is embedded into concrete and consequently confinement provided must be validated with tests on embedded CFRP grid. Standard (150 mm x 300 mm) concrete cylinders were cast both with and without the embedded CFRP grid. The cylinders were tested in compression to determine the effect of the CFRP grid on their strength and ductility. A significant improvement both in strength and ductility was observed for the cylinders with the embedded CFRP grid compared to the control cylinders depending on the amount of confinement reinforcement used.
Keywords - FRP Composites, Concrete Strength, Confinement, Ductility.